1. Field of the Invention:
This invention relates to a winch for use in a side crane of a construction machinery, and more particularly to a power transmission in a double-drum winch in which the respective drums are independently operated for the desired operation of the hook and the boom.
2. Description of the Prior Art:
In a prior art winch of the type described above heretofore known, since the two drums for the operation of the hook and the boom, respectively, cannot be independently operated from each other, an operation such as to move the hook upwardly or downwardly by one of the drums while the boom is moved upwardly or downwardly by the other drum can not be carried out. Thus, the range of modes of operation is necessarily limited. Further, the prior art winch is provided with a plurality of operating levers for operating for example, the hook brake, the boom brake, the hook gear, the boom gear, the transmission and the clutches of the winch, thereby tending to cause erroneous operation of the winch and early fatigue of the operator. Thus, an operator skilled in the operation of the winch is required.
In view of the above described disadvantages of the prior art double-drum winch, this invention contemplates to eliminate those disadvantages.